Comparative analysis of closed loop stepping motor and servo motor
Comparative analysis of closed-loop stepping motor and Servo Motor Servo motor is highly praised and talked about by current engineers. It is almost unimaginable to mention motion control without talking about servo motor, engineers are obsessed with the closed-loop control of servo motors, indulging in the advantages of high response, high speed and high precision, and really'Three highs'.
However, as the saying goes, the servo stepping motor has its inevitable defects: 1.
Unable to stand still: due to the closed-loop control, the structure of the servo motor itself and the characteristics of the motor determine that the servo motor cannot stand still absolutely when it stops, under the condition of small load disturbance or good parameter debugging of the servo motor, the servo motor always fluctuates between plus or minus 1 pulse (
By observing the value of the encoder position on the servo driver, it fluctuates between plus or minus 1 all the time).
This is a factor that affects accuracy in image processing. 2.
Overshoot: when changing from high speed to low speed or at rest, it is inevitable to overshoot for a certain distance and then correct it back.
When the controller sends a pulse to the servo motor, the servo motor often does not take one pulse, but 3 pulses, and then returns 2 pulses.
This is fatal to occasions where one pulse and one pulse motion are required, and overshoot is absolutely not allowed. 3.
Debugging is complicated: there are hundreds of parameters in the servo driver and hundreds of pages in the instruction manual, which really makes the novice feel embarrassed;
Replacing a brand of servo motor will also give the veteran a headache.
This also brings a lot of work to after-sales service and maintenance. 4.
Low speed peristalsis: peristalsis or crawling occurs when the servo motor is running at low speed.
The closed-loop stepping motor perfectly solves the above problems.
Since the closed-loop stepping motor is not simply equipped with an encoder for the stepping motor, it is designed and developed according to the working principle of the servo motor system.
It uses 32-bit DSP as the main processor to ensure the high response and high speed of the whole system, and can adjust the current of the motor every 25 microseconds, the encoder with 10000 pulses/turns is standard, and it is an encoder with a metal code disc, which not only ensures accuracy, but also ensures high adaptability, stability and reliability to environment, temperature and vibration, even better than servo motors using glass encoder.
First of all, the closed-loop stepping motor is absolutely stationary when it is stationary because its body is a stepping motor.
Secondly, the closed-loop stepping motor will not overshoot (Because the characteristics of the stepping motor are not overshoot).
Third, debugging and use is very simple. It only needs to adjust the positions of the three potentiometers of the driver. Not only can the equipment manufacturer use it, but also the equipment user can use it. The requirements for users are extremely low.
Fourth, the driver uses real sine wave, vector and filtering methods to control the current, and the minimum rotation speed can be controlled at 0.
2 rpm, and the motor runs very smoothly and stably, which even servo motors cannot do (
In general, servo motors can theoretically achieve 1 rpm, but in practical applications, they cannot achieve 1 rpm, which is roughly above 5 rpm).
TAG closed loop stepper motor